refactor fonts: do all text layout via the Fonts struct

egui/src/containers/combo_box.rs

@@ -180,8 +180,7 @@ fn combo_box(
         let icon_size = Vec2::splat(ui.spacing().icon_width);
 
         let text_style = TextStyle::Button;
-        let font = &ui.fonts()[text_style];
+        let galley = ui.fonts().layout_no_wrap(text_style, selected.into());
-        let galley = font.layout_no_wrap(selected.into());
 
         let width = galley.size.x + ui.spacing().item_spacing.x + icon_size.x;
         let width = width.at_least(full_minimum_width);

egui/src/painter.rs

@@ -173,8 +173,9 @@ impl Painter {
 
     pub fn error(&self, pos: Pos2, text: impl std::fmt::Display) -> Rect {
         let text_style = TextStyle::Monospace;
-        let font = &self.fonts()[text_style];
+        let galley =
-        let galley = font.layout_multiline(format!("🔥 {}", text), f32::INFINITY);
+            self.fonts()
+                .layout_multiline(text_style, format!("🔥 {}", text), f32::INFINITY);
         let rect = Align2::LEFT_TOP.anchor_rect(Rect::from_min_size(pos, galley.size));
         let frame_rect = rect.expand(2.0);
         self.add(Shape::Rect {
@@ -291,8 +292,9 @@ impl Painter {
         text_style: TextStyle,
         text_color: Color32,
     ) -> Rect {
-        let font = &self.fonts()[text_style];
+        let galley = self
-        let galley = font.layout_multiline(text.into(), f32::INFINITY);
+            .fonts()
+            .layout_multiline(text_style, text.into(), f32::INFINITY);
         let rect = anchor.anchor_rect(Rect::from_min_size(pos, galley.size));
         self.galley(rect.min, galley, text_style, text_color);
         rect

egui/src/ui.rs

@@ -1245,9 +1245,8 @@ impl Ui {
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> InnerResponse<R> {
         self.wrap(|ui| {
-            let font = &ui.fonts()[text_style];
+            let row_height = ui.fonts().row_height(text_style);
-            let row_height = font.row_height();
+            let space_width = ui.fonts().glyph_width(text_style, ' ');
-            let space_width = font.glyph_width(' ');
             let spacing = ui.spacing_mut();
             spacing.interact_size.y = row_height;
             spacing.item_spacing.x = space_width;
@@ -1290,9 +1289,8 @@ impl Ui {
         add_contents: impl FnOnce(&mut Ui) -> R,
     ) -> InnerResponse<R> {
         self.wrap(|ui| {
-            let font = &ui.fonts()[text_style];
+            let row_height = ui.fonts().row_height(text_style);
-            let row_height = font.row_height();
+            let space_width = ui.fonts().glyph_width(text_style, ' ');
-            let space_width = font.glyph_width(' ');
             let spacing = ui.spacing_mut();
             spacing.interact_size.y = row_height;
             spacing.item_spacing.x = space_width;

egui/src/widgets/button.rs

@@ -106,11 +106,11 @@ impl Button {
         }
         let total_extra = button_padding + button_padding;
 
-        let font = &ui.fonts()[text_style];
         let galley = if ui.wrap_text() {
-            font.layout_multiline(text, ui.available_width() - total_extra.x)
+            ui.fonts()
+                .layout_multiline(text_style, text, ui.available_width() - total_extra.x)
         } else {
-            font.layout_no_wrap(text)
+            ui.fonts().layout_no_wrap(text_style, text)
         };
 
         let mut desired_size = galley.size + 2.0 * button_padding;
@@ -210,19 +210,18 @@ impl<'a> Widget for Checkbox<'a> {
             text_color,
         } = self;
 
-        let text_style = TextStyle::Button;
-        let font = &ui.fonts()[text_style];
-
         let spacing = &ui.spacing();
         let icon_width = spacing.icon_width;
         let icon_spacing = ui.spacing().icon_spacing;
         let button_padding = spacing.button_padding;
         let total_extra = button_padding + vec2(icon_width + icon_spacing, 0.0) + button_padding;
 
+        let text_style = TextStyle::Button;
         let galley = if ui.wrap_text() {
-            font.layout_multiline(text, ui.available_width() - total_extra.x)
+            ui.fonts()
+                .layout_multiline(text_style, text, ui.available_width() - total_extra.x)
         } else {
-            font.layout_no_wrap(text)
+            ui.fonts().layout_no_wrap(text_style, text)
         };
 
         let mut desired_size = total_extra + galley.size;
@@ -322,18 +321,17 @@ impl Widget for RadioButton {
             text_color,
         } = self;
 
-        let text_style = TextStyle::Button;
-        let font = &ui.fonts()[text_style];
-
         let icon_width = ui.spacing().icon_width;
         let icon_spacing = ui.spacing().icon_spacing;
         let button_padding = ui.spacing().button_padding;
         let total_extra = button_padding + vec2(icon_width + icon_spacing, 0.0) + button_padding;
 
+        let text_style = TextStyle::Button;
         let galley = if ui.wrap_text() {
-            font.layout_multiline(text, ui.available_width() - total_extra.x)
+            ui.fonts()
+                .layout_multiline(text_style, text, ui.available_width() - total_extra.x)
         } else {
-            font.layout_no_wrap(text)
+            ui.fonts().layout_no_wrap(text_style, text)
         };
 
         let mut desired_size = total_extra + galley.size;

egui/src/widgets/label.rs

@@ -150,13 +150,14 @@ impl Label {
 
     pub fn layout_width(&self, ui: &Ui, max_width: f32) -> Galley {
         let text_style = self.text_style_or_default(ui.style());
-        let font = &ui.fonts()[text_style];
         let wrap_width = if self.should_wrap(ui) {
             max_width
         } else {
             f32::INFINITY
         };
-        let galley = font.layout_multiline(self.text.clone(), wrap_width); // TODO: avoid clone
+        let galley = ui
+            .fonts()
+            .layout_multiline(text_style, self.text.clone(), wrap_width); // TODO: avoid clone
         self.valign_galley(ui, text_style, galley)
     }
 
@@ -263,7 +264,7 @@ impl Label {
                 -2.0
             } else {
                 let normal_text_heigth = ui.fonts()[TextStyle::Body].row_height();
-                let font_height = ui.fonts()[text_style].row_height();
+                let font_height = ui.fonts().row_height(text_style);
                 (normal_text_heigth - font_height) / 2.0 - 1.0 // center
 
                 // normal_text_heigth - font_height // align bottom
@@ -293,8 +294,8 @@ impl Widget for Label {
             let first_row_indentation = max_width - ui.available_size_before_wrap().x;
 
             let text_style = self.text_style_or_default(ui.style());
-            let font = &ui.fonts()[text_style];
+            let mut galley = ui.fonts().layout_multiline_with_indentation_and_max_width(
-            let mut galley = font.layout_multiline_with_indentation_and_max_width(
+                text_style,
                 self.text.clone(),
                 first_row_indentation,
                 max_width,

egui/src/widgets/plot.rs

@@ -649,8 +649,7 @@ impl Prepared {
 
             let text = emath::round_to_decimals(value_main, 5).to_string(); // hack
 
-            let font = &ui.fonts()[text_style];
+            let galley = ui.fonts().layout_multiline(text_style, text, f32::INFINITY);
-            let galley = font.layout_multiline(text, f32::INFINITY);
 
             let mut text_pos = pos_in_gui + vec2(1.0, -galley.size.y);
 

egui/src/widgets/selected_label.rs

@@ -40,16 +40,15 @@ impl Widget for SelectableLabel {
     fn ui(self, ui: &mut Ui) -> Response {
         let Self { selected, text } = self;
 
-        let text_style = TextStyle::Button;
-        let font = &ui.fonts()[text_style];
-
         let button_padding = ui.spacing().button_padding;
         let total_extra = button_padding + button_padding;
 
+        let text_style = TextStyle::Button;
         let galley = if ui.wrap_text() {
-            font.layout_multiline(text, ui.available_width() - total_extra.x)
+            ui.fonts()
+                .layout_multiline(text_style, text, ui.available_width() - total_extra.x)
         } else {
-            font.layout_no_wrap(text)
+            ui.fonts().layout_no_wrap(text_style, text)
         };
 
         let mut desired_size = total_extra + galley.size;

egui/src/widgets/slider.rs

@@ -441,8 +441,10 @@ impl<'a> Slider<'a> {
 impl<'a> Widget for Slider<'a> {
     fn ui(mut self, ui: &mut Ui) -> Response {
         let text_style = TextStyle::Button;
-        let font = &ui.fonts()[text_style];
+        let height = ui
-        let height = font.row_height().at_least(ui.spacing().interact_size.y);
+            .fonts()
+            .row_height(text_style)
+            .at_least(ui.spacing().interact_size.y);
 
         let old_value = self.get_value();
 

egui/src/widgets/text_edit.rs

@@ -300,13 +300,13 @@ impl<'t> TextEdit<'t> {
         } = self;
 
         let text_style = text_style.unwrap_or_else(|| ui.style().body_text_style);
-        let font = &ui.fonts()[text_style];
+        let line_spacing = ui.fonts().row_height(text_style);
-        let line_spacing = font.row_height();
         let available_width = ui.available_width();
         let mut galley = if multiline {
-            font.layout_multiline(text.clone(), available_width)
+            ui.fonts()
+                .layout_multiline(text_style, text.clone(), available_width)
         } else {
-            font.layout_single_line(text.clone())
+            ui.fonts().layout_single_line(text_style, text.clone())
         };
 
         let desired_width = desired_width.unwrap_or_else(|| ui.spacing().text_edit_width);
@@ -481,11 +481,11 @@ impl<'t> TextEdit<'t> {
                     response.mark_changed();
 
                     // Layout again to avoid frame delay, and to keep `text` and `galley` in sync.
-                    let font = &ui.fonts()[text_style];
                     galley = if multiline {
-                        font.layout_multiline(text.clone(), available_width)
+                        ui.fonts()
+                            .layout_multiline(text_style, text.clone(), available_width)
                     } else {
-                        font.layout_single_line(text.clone())
+                        ui.fonts().layout_single_line(text_style, text.clone())
                     };
 
                     // Set cursorp using new galley:
@@ -517,11 +517,11 @@ impl<'t> TextEdit<'t> {
             .galley(response.rect.min, galley, text_style, text_color);
 
         if text.is_empty() && !hint_text.is_empty() {
-            let font = &ui.fonts()[text_style];
             let galley = if multiline {
-                font.layout_multiline(hint_text, available_width)
+                ui.fonts()
+                    .layout_multiline(text_style, hint_text, available_width)
             } else {
-                font.layout_single_line(hint_text)
+                ui.fonts().layout_single_line(text_style, hint_text)
             };
             let hint_text_color = ui.visuals().weak_text_color();
             ui.painter()

epaint/src/shape.rs

@@ -132,8 +132,7 @@ impl Shape {
         text_style: TextStyle,
         color: Color32,
     ) -> Self {
-        let font = &fonts[text_style];
+        let galley = fonts.layout_multiline(text_style, text.into(), f32::INFINITY);
-        let galley = font.layout_multiline(text.into(), f32::INFINITY);
         let rect = anchor.anchor_rect(Rect::from_min_size(pos, galley.size));
         Self::Text {
             pos: rect.min,

epaint/src/text/font.rs

@@ -222,6 +222,7 @@ impl Font {
             .and_then(|gi| gi.1.uv_rect)
     }
 
+    /// Width of this character in points.
     pub fn glyph_width(&self, c: char) -> f32 {
         self.glyph_info(c).1.advance_width
     }

epaint/src/text/fonts.rs

@@ -6,7 +6,10 @@ use std::{
 
 use crate::{
     mutex::Mutex,
-    text::font::{Font, FontImpl},
+    text::{
+        font::{Font, FontImpl},
+        Galley,
+    },
     Texture, TextureAtlas,
 };
 
@@ -259,6 +262,65 @@ impl Fonts {
 
         buffered_texture.clone()
     }
+
+    /// Width of this character in points.
+    pub fn glyph_width(&self, text_style: TextStyle, c: char) -> f32 {
+        self.fonts[&text_style].glyph_width(c)
+    }
+
+    /// Height of one row of text. In points
+    pub fn row_height(&self, text_style: TextStyle) -> f32 {
+        self.fonts[&text_style].row_height()
+    }
+
+    /// Always returns at least one row.
+    /// Will line break at `\n`.
+    pub fn layout_no_wrap(&self, text_style: TextStyle, text: String) -> Galley {
+        self.layout_multiline(text_style, text, f32::INFINITY)
+    }
+
+    /// Typeset the given text onto one row.
+    /// Any `\n` will show up as the replacement character.
+    /// Always returns exactly one `Row` in the `Galley`.
+    ///
+    /// Most often you probably want `\n` to produce a new row,
+    /// and so [`Self::layout_no_wrap`] may be a better choice.
+    pub fn layout_single_line(&self, text_style: TextStyle, text: String) -> Galley {
+        self.fonts[&text_style].layout_single_line(text)
+    }
+
+    /// Always returns at least one row.
+    /// Will wrap text at the given width.
+    pub fn layout_multiline(
+        &self,
+        text_style: TextStyle,
+        text: String,
+        max_width_in_points: f32,
+    ) -> Galley {
+        self.layout_multiline_with_indentation_and_max_width(
+            text_style,
+            text,
+            0.0,
+            max_width_in_points,
+        )
+    }
+
+    /// * `first_row_indentation`: extra space before the very first character (in points).
+    /// * `max_width_in_points`: wrapping width.
+    /// Always returns at least one row.
+    pub fn layout_multiline_with_indentation_and_max_width(
+        &self,
+        text_style: TextStyle,
+        text: String,
+        first_row_indentation: f32,
+        max_width_in_points: f32,
+    ) -> Galley {
+        self.fonts[&text_style].layout_multiline_with_indentation_and_max_width(
+            text,
+            first_row_indentation,
+            max_width_in_points,
+        )
+    }
 }
 
 impl std::ops::Index<TextStyle> for Fonts {